Metallic structure



March 26, 1946. ...L P. TARBOX METALLIC STRUCTURE Filed oct. 19, 1944 INVENTOR fifi/11111111 l l I l l l l l I l Patented Mar. 26, 1946 UNITED STATES PATENT oFElcE METALLIC STRUCTURE John P. Tarbox, Philadelphia, Pa., assignor to Edward G. Budd Manufacturing Company, Philadelphia, Pa., a corporation of Pennsylvania Application October 19, 1944, Serial No. 559,333

3 Claims.

larly to means for securing reinforced skin sheets or skin blankets to the internal framework of such structures.

VIt has heretofore been proposed to secure such` reinforced skin structures to the transverse frame members by means of clips overlapping the respective reinforcements and frame members and secured to each.

It is an object of my invention to provide a construction wherein the frame members and reinforcements of the skin themselves are provided with overlapping `ioini; structure through which they may be readily secured together without the use of separate clips. the joint parts being extended at substantially right angles to the skin so that they are readily accessible forjoinder by welding tongs or the like. A

To this end, integral tabs are struck out and bent at substantially right angles from said frame members, and the reinforced skin sheet to be attached thereto is provided with side walls adapted to overlap with and be secured to the tabs.

Other and further objects and advantages and the manner in which they are attained will be apparent from the following detailed description of an exemplary embodiment of the invention, reference being had to the drawing forming a part of this specification.

In the drawing:

Figure 1 is a diagrammatic sectional view through an airplane wing to which the invention is shown applied;

Figure 2 is an enlarged fragmentary detail View showing the manner of attachment of the reinforced skin sheet to the chord of a rib;

Figure 3 is a fragmentary detail section, the section being taken on the line 3-3 of Figure 2; and

Figure 4 is a fragmentary perspective view of a portion of the rib with parts in section, the section being taken substantially along the line 4-4 of Figure 2.

As representative of the application of the invention, the wing I of an airplane is shown in Figure 1, the same comprising a leading edge section 2, a central section 3, and a trailing section 4. 'I'he central section comprises ribs 5 and reinforced skin sheets or skin blankets 6. The ribs may include bipartite overlapping webs 1 and struts 8 and edge chords or cap strips 9. As shown in Figures 3 and 4, the cap strips 9 here are of angular shape having a relatively wide flange III disposed parallel to the skin blanket.

The cap strips preferably are Z-shaped and the outer ilange I0 may be reinforced by an inturned or outturned strip II, either integral or welded thereto.

The skin blanket 6 comprises a skin sheet I2 and a plurality of stringers I3. The stringere may have various cross-sectional shapes but one characteristic which is common is that they have at least one wall I4 which is disposed approximately perpendicular to the cap strip 9. One side of the strngers shown herein has such a vertical wall disposed adjacent and in iinal assembly secured to a vertical wall I5 of an adjacent stringer, the latter wall being extended to form an arm I6 which is directly attached to the outer ilange I0 of the cap strip, as by welding. 1

During formation of the cap strip 9 a plurality of clips or tabs I1 are struck out from the outer flange I0' and turned up at right angles. I'heir location is determined vby the dimensions of the stringers which are to be attached, the tabs being located where they will lie alongside a side wall I4 or I5 or both of the stringers.

When the skin blanket and rib cap strips are brought together the tabs, which now lie alongside thewalls I4 and I5 or between them, are welded to these vertical walls. Afterward the arms I6 are welded to the cap strip.

Considerable vertical and longitudinal (of the stringers) adjustment of the skinblanket is permitted before the tab connections are made, the arms I6 being resilient to permit them to be adjusted before welding.

The strips II on the cap strips and the arms I6 which are triangulated over the openings left in the cap strip when the tabs are formed, provide adequate strength compensation forthe openings.

It is thus seen that the invention provides a very simple and inexpensive yet strong and convenient construction. If desired, of course, tabs may be struck in like manner from a flange of a Stringer when it lies alongside and parallel to the top of the cap strip, vas does the end of the arm I6 here, to be attached to the side of the cap strip. In all cases the connection of the tab to the adjacentside wall is made by shear means. The uncut metal at the root end of the tab will strongly resist being pulled out, particularly when the parts are made of a very strong tough metal such as cold-rolled stainless steel. f

While one embodiment of the invention has been described it is to be understood that there may be various embodiments within the limits of claims. What iscia'imed is: l

1. In a sheet metal structure, a frame mem- 2... l.. 4 V n l.. I

the prior art and the scope of the subioined ber having a nange portion forming In attaching tace, tabs cut out along three sides from said face and bent at an angle to said face along the fourth side, a reinforced skin blanket comprising a skin sheet and 'reinforcing stringere secured to said sheet, said stringers having portions which overlap said tabs on the side thereof and are secured thereto, and at least one side wall of adjacent stringers being extended by a bracing portion projecting from the portion overlapping an. ad-

` jacent tab and having its .end overlapping the attaching face of the frame member and thereto. f

2. In a sheet metal structure. a frame member having a flange which forms an attaching face.

the outer edge of the ilang'e being turned back 20 in a return iiange, attaching tabs eut out of said face along three sides and bent at an angle to said face along the fourth sideland a reinforcing strip secured along the length o! the return flange and extending away from said attaching face to compensate for the weakening caused by cutting out thetabs.

3. In fa sheet metal structure, a nrst frame member having a thin wall and a fiat tab struck therefrom with one edge left integrally united. thereto along atransverse line and with its plane parallel to the line of attachment, a second frame member disposed transversely of the nrst frame 

